hooleyboy

I got board today and installed a Renntech 168mm pulley. After the install I tossed it on the dyno. Only to make 450whp and 530wtq. We only did about 8 pulls in the course of 15min or so.

I came to the conclusion I hate modding my car in the AZ heat. Shop temp was 107 degrees and 31% humidity.

On the plus side the car feels smoother, strangely enough. Over all it just made my car feel better. Kind of one of those things you cant explain. Maybe the Renntech pulley has less vibration than a stock 152mm pulley I was using.

IMO, the jury is still out on what kind of power numbers I will see with the new pulley and cooler temps. Also A/F needs to be adjusted. I need a bit more fuel.

Right now, thats it for performance mods until it cools off. In this heat its even more important to do back to back same day dyno pulls. I'm 450 one day then 435 then back to 450hp. Its getting even harder to tell where my car really stands at this point.

JonMBZ

Weren't you getting those numbers before without the long tubes and pulley? Should have dynod it before you changed the pulley. Hopefully you didn't shell out too much for that pulley.

jturkel

Mike,

I'm sure your car is faster. The heat is really killing our cars. I was posting up in the header thread the other day about my racing Brock. You were in my car that one night in March or April after my pulley and tune when I ran Brock. And he only pulled a little bit (that was with his longtubes).

I raced him two weeks ago with Trevor in his car, and he pulled me like 2 cars WITH the addition of my headers. You can really feel the difference. When I went out the other night and it was 80 compared to the 105 I ran Brock in, my car was insanely fast. Those temp differences are causing the confusion.

I'm not planning on putting my car on a dyno, going to the track, or seriously taking my boost numbers until at least early October. It just isnt worth the aggravation.

What are your IATs though? I would imagine yours are significantly lower than mine (idk what mine are tho) considering you are running two heat exchangers, a large pump, and less boost than me.

billapex

I'm confused. The stock pulley is 152mm and the Renntech is 168mm? And are you saying you're surprised you made less hp with the larger pulley? Not sure I'm following...

moparrbust

The heat we have to deal with is killer on performance. The best way for me to tell if new mods were worth while is to take the car to the track and see if I can run the same times(or slightly slower) I did in COOL weather. Then when it actually cools off again you WILL run new best times.

jturkel

larger crank pulley = more boost
smaller supercharger pulley = more boost

example:
stock C32 pulley (158 or 168, i dont remember) = 14.5PSI
178mm Crank Pulley ~17 PSI
181mm~19 PSI
185mm~21-22 PSI

hooleyboy

Yes back when I first finished my SC project I was making 450whp and 522wtq on a cool afternoon. my last dyno before I did the long tube header project and under 100 or so degrees I made 438whp then with the headers I was back up to the 450 area. With the pulley installed I made 450 again in 107 degree heat. I'm kinda confused by the loss and gain of power as well. Only think I can think is the heat is just to much.

We didnt monitor it today but I may be pulling some timing in this heat.

Larger crank pulleys on MBZ Kompressor cars make more HP. Smaller supercharger pulleys also make more HP, but know one really make a supercharger pulley.

For sure, its still damn fast. I guess to putt down 450whp in this heat is kinda good all things aside.

Yeah its faster. It has to be. I went though this same ordeal when I was NA. I was struggling to make 350whp every time i hit the dyno. That was when I was modding last summer. Here I am pounding around the 450whp mark this summer.

If anything is a good indicator the TQ number down low went up, and thats before the motor can really be affected by the heat outside and the engine.

hooleyboy

Turk,
It seems ironic that as soon as the heat hits out here everyone from AZ starts complaining of the effects on the cars. My self included.

Just for S&G I checked the DA from Dragtimes at Speedworld and it was 4988ft! and that was at the 9pm time slot! The time I race at. Thats like racing a mile in the sky or not to far off!

New found respect for our AMG friends in Denver.

jturkel

yup, and if you think thats bad, try going to SIR in Tucson. Brock went there 3 weeks ago and ran a mid 13 @ 107. Oh, and the DA was 6800 lol. He said he was the second fastest car their, with a C6 Z06 trapping like 115 or 116.

edit: just talked with brock. he ran a 13.5 @ 108.2 at 6300 DA. C6 Z06 was a 12.4 at 115. New driver apparently. Just to show how much temps and DA can make an affect. I think altitude kills N/A more than F/I but temps kill F/I like our cars more than N/A imo. Not sure if that is proven anywhere, just my personal experiences with both.

E55AMGFan

As I've seen numerous times again, high temps= worst friend for a sc/turboed car. As soon as it gets much cooler you'll pick up power and torque.

c32used

Your car rocks regardless!

E55AMGFan

Exactly! and it sure got the numbers and results to prove that with ease.

splinter

+2

Just wait until those frigid AZ temperatures return. It'll pull something fierce.

hooleyboy

Yeah I'm thinking so too. This was just a spur of the moment thing. We had the 168mm pulley kicking around. We just tossed it on and through it on the dyno to see if it made any power in a total of 8, 3rd gear pulls then took it off the dyno and I went home. There was basically no time for the ECU to adapt for the new pulley in the time we had it on the dyno. I will be back on the dyno this week for a custom retune.

FrankW

i'll trade you my car! lol

hooleyboy

Thank ya very much. If I only didnt drive it like an old man most of the time.

At this years Fomoso tarck event, I got the trailer and truck ready to haul it out there. Complete with 180+mm pulley 109oct race fuel map and some other weapons. I hope to put down a jaw dropping time

I cant wait, I get to drag my lady out to the track again in 50 degree temps. She's gonna love that if the DA drops below 2000ft I will put down a fast time. I've already started my Christmas shopping to see if that helps make the cooler temps get here faster.

jturkel

when is this? maybe i'll join

i'll record it. i know your g/f has some difficulty with the camera lol. and i may steal your DRs for a couple runs too

E55AMGFan

Retune should help a bit but the most help in consistent power will be the IATs you're getting at the shop/dyno which is not helping at all at 107 degrees as the temperature in there. Easily I wont be suprised if you make more power on the street and especially during the AZ nights vs. what you dynoed at the shop. This is easily the case where the IAT themselves can't be too low due to insane environmental temperatures and humidity. It would be nice to dyno on a cool AZ night vs. the day, I won't be suprised if it makes a good amount more of power and torque especially if you retune the ecu.

Get that 180mm, Race gas, Slicks or DRs, and head out on a MUCH COOLER temperature time period. How I see it the CM30 could be on there along with an upgraded HE, they won't be able to help a bit if what you have around you is scorching heat.

The formula of Cool temps, consistent cooling mods, and a nasty power such as what you got, and traction = ownage!

hooleyboy

I'm not sure when it is, its not planed yet.

Sure thing Your filming. Trust me, you know my lady she will love you if you take over that roll... And yes you can use my slicks any time. Turk going for the 12's this winter and its going to happen for sure.

hooleyboy

I feeling you 100% on the street power. We have been having A/C issues in the shop and with the bays open in the summer time. It can get down right unbearable in the shop. If Im in the shop I will go through a few shirts its just that hot. When we turn all the dyno fans on it only blows hot air.

I have a custom cooling combo on my car. Twin heat exchangers big pump and independent ran system. Dont think its helping in this heat much. So again I agree with you. cant cool down a car with hot air.

I ran my outside temp sensor down to my intercooler "y" and I've come to the conclusion that the temp numbers it reads are way wrong.

hooleyboy

I did that last year after all my NA mods, 13.2 bone stock 291whp. 100 degree heat (At night!) I ran a 13.2 with 350whp. It was a frustrating summer. But it made scene that my car was loosing the feel of about 60whp in these temps.

jturkel

yah, as much as the cooling mods help prevent heat soak at the track or in regular driving conditions and traffic, when outside ambient temps are 110-115, there isnt much to help keep your IATs down besides meth injection or nitrous for cooling purposes. AZ weather just blows.....and gas too lol.

you definitely need to get a legit IAT gauge then. thats why i'm getting that dashdyno. that way you really know when and why your car is running well or is running like a$$.

E55AMGFan

Couldn't agree more myself, a common case with those on boost is to have good IATs, high heat temps don't help no matter how good of cooling you got on hand. Be patient as things should shape up soon, once the ECU gets a retune and you have some cooler temps, things should turn out pretty good.

Since you got a custom cooling setup for your car, why can't you make a custom cooling setup for the shop and the shirts you wear? I see it now you'll tell others "I own a C55, even though it lacks ventilated seats from the factory my ventilated a/c shirt makes up for that feature MB left out."

hooleyboy

Yeah I need a good temp gauge.. So I'm getting a Aircraft gauge that will tell you the inside and outside temps along with the diff between the two.



I'm getting this... Its the last one on the page.
http://www.aircraftspruce.com/catalo...davtron307.php

jturkel

my gawd mike. an aircraft gauge? are you rigging up some wings or something to put on your car?

model 307FD? pretty steep....though i suppose you cant go wrong with an aircraft gauge on a car? has to be pretty damn accurate im guessing lol